Distinctive clinical features of human bocavirus in children younger than 2 years

Moriyama, Yoko; Hamada, Hiromichi; Okada, Mineyuki; Tsuchiya, Nozomi; Maru, Hiromi; Shirato, Yuri; Maeda, Yasuhiro; Hirose, Yosuke; Yoshida, Masaki; Omura, Yoh; Honda, Takafumi; Muto, Ayako; Hayashi, Kitami; Terai, Masaru

The main clinical features in HBoV-positive patients are respiratory distress and hypoxia, which are frequently observed in LRTI patients with RSV. In our study, oxygen saturation on admission shows that hypoxia was more severe in HBoV-positive patients than in RSV-positive patients. Moreover, the short duration from disease onset to admission shows that respiratory distress and hypoxia progress rapidly in HBoV-positive patients. Oikawa et al. recently reported a severe case with HBoV associated with plastic bronchitis, which necessitated mechanical ventilation [21] . Many previous reports have not described severe cases of HBoV infection; however, the sample size is small and the studies were retrospective. In our study, one out of 18 patients had severe pneumonia and remained hospitalized for 19 days. A larger number of cases with HBoVpositive LRTI must be accumulated to discuss the disease severity. Patients with RSV infection sometimes need intensive care. Pediatricians have specifically addressed the care and protection of this infection. One reason is that the RSV infection is frequently found in infants who are younger than 3 months. Furthermore, patients younger than 3 months often require intensive care. In contrast, the minimum age of HBoV-positive patient is 5 months in our study. Therefore, the difference in the age of patients might affect the disease severity.